Traditionally, inkjet printing is accomplished by one of two technologies referred to as “drop-on-demand” and “continuous” printing. In both, liquid, such as ink, is fed through channels formed in a print head. Each channel includes a nozzle from which droplets are selectively extruded and deposited upon a recording surface.
Continuous liquid printing uses a pressurized liquid source that produces a stream of drops some of which are selected to contact a print media while other are selected to be collected and either recycled or discarded. For example, when no print is desired, the drops (commonly referred to as non-print drops) are deflected into a capturing mechanism (commonly referred to as a catcher, interceptor, or gutter) and either recycled or discarded. When printing is desired, the drops (commonly referred to as print drops) are not deflected and allowed to strike a print media. Alternatively, deflected drops can be allowed to strike the print media, while non-deflected drops are collected in the capturing mechanism.
After the non-print liquid drop contacts the catcher, it flows down the catcher face. Drag causes the liquid to slow down which can cause the liquid layer (also referred to as a liquid film) to become thicker. Increasing the thickness of the liquid film reduces the clearance between the liquid film and the print drops. If there is insufficient clearance between the liquid film and the print drops, the ink film can contact the print drops resulting in print defects.
As such, there is an ongoing effort to improve catcher performance in continuous printing systems.